我如今是一名Android Developer,大学的我曾是一名ACMer,为了不想让算法淡出我的记忆,故重拾LeetCode之Algorithm,语言选择的是Java,题库会一点点完善起来,按简单,中等,困难分类,相应难度下按题号排序,工程代码在project目录中,相关解题都在note目录中,欢迎star。





# Title Tag
1 Two Sum Array, Hash Table
7 Reverse Integer Math
9 Palindrome Number Math
13 Roman to Integer Math, String
14 Longest Common Prefix String
20 Valid Parentheses Stack, String
21 Merge Two Sorted Lists Linked List
26 Remove Duplicates from Sorted Array Array, Two Pointers
27 Remove Element Array, Two Pointers
28 Implement strStr() Two Pointers, String
35 Search Insert Position String
38 Count and Say String
53 Maximum Subarray Array, Dynamic Programming, Divide and Conquer
58 Length of Last Word String
66 Plus One Array, Math
67 Add Binary Math, String
69 Sqrt(x) Binary Search, Math
70 Climbing Stairs Dynamic Programming
83 Remove Duplicates from Sorted List Linked List
88 Merge Sorted Array Array, Two Pointers
100 Same Tree Tree, Depth-first Search
101 Symmetric Tree Tree, Depth-first Search, Breadth-first Search
104 Maximum Depth of Binary Tree Tree, Depth-first Search
107 Binary Tree Level Order Traversal II Tree, Breadth-first Search
108 Convert Sorted Array to Binary Search Tree Tree, Depth-first Search
110 Balanced Binary Tree Tree, Depth-first Search
111 Minimum Depth of Binary Tree Tree, Depth-first Search, Breadth-first Search
112 Path Sum Tree, Depth-first Search
118 Pascal’s Triangle Array
119 Pascal’s Triangle II Array
121 Best Time to Buy and Sell Stock Array, Dynamic Programmin
122 Best Time to Buy and Sell Stock II Array, Greedy
543 Diameter of Binary Tree Tree


# Title Tag
2 Add Two Numbers Linked List, Math
3 Longest Substring Without Repeating Characters Hash Table, Two Pointers, String
8 String to Integer (atoi) Math, String
15 3Sum Array, Two Pointers
17 Letter Combinations of a Phone Number String, Backtracking
19 Remove Nth Node From End of List Linked List, Two Pointers
33 Search in Rotated Sorted Array Arrays, Binary Search
43 Multiply Strings Math, String
49 Group Anagrams Hash Table, String
50 Pow(x, n) Math, Binary Search
56 Merge Intervals Array, Sort
554 Brick Wall Hash Table


# Title Tag
4 Median of Two Sorted Arrays Array, Binary Search, Divide and Conquer
10 Regular Expression Matching String, Dynamic Programming, Backtracking
23 Merge k Sorted Lists Linked List, Divide and Conquer, Heap
25 Reverse Nodes in k-Group Linked List
44 Reverse Nodes in k-Group String, Dynamic Programming, Backtracking, Greedy
57 Insert Interval Array, Sort